Conventional confocal chromatic microscope system is installed on desktop so as to perform a vertical or lateral scan on an object for obtaining a surface profile of the object. Due to large system volume inducing disadvantages of occupying too much space, there has a limitation for utilizing the conventional confocal chromatic microscope system to perform surface profile measurement on the object, such as 8-inch wafer having a plurality of large scale integration (LSI) chips formed thereon, thereby reducing practicability and convenience of the entire configuration.
In the conventional arts, such as US. Pub. No. 2004/0051879, it disclosed a confocal displacement sensor wherein, through an advanced arrangement of optical outputs relative to an imaging optic in the object area of displacement sensor, real images of the optical outputs can be created at different heights. In this art, two measurement beams are created by two planar light sources, and two planar high-resolution cameras are arranged for light intensity detection. The height position of the scanned points of the surface can be calculated and the surface to be measured can be measured simultaneously at a number of scanning points. In addition, it is also known that a color sensing unit is utilized to detect the intensity ratio of the object surface, whereby a surface height or depth can be obtained by calculation according to relationship between color intensity and depth.
However, since the reflection rate with respect to RGB color is varied with the property of object surface, such as color of the object surface, it is necessary to establish a depth relation curve corresponding to the reflection rate of different colors for the surface profile measurement, which is inconvenient for the inspection operator. In addition, another drawback is that the slit structure is indispensable for receiving the object light from the object in the convention configuration, so that a cross talk caused by an overlap between neighboring object light, unfocused light, and stray light will be generated inevitably, thereby decreasing effect of image detection resolution.
Accordingly, there is a need for providing a chromatic confocal microscope system and signal process method to overcome the disadvantages generated by the conventional arts.